Situation: logged on as local admin, downloaded SP3 from MS download site; installation runs OK through extraction of files, then stops with the following message. "You do not have permission to update Windows XP. Contact your system administrator."
One odd situation about this computer which might be pertinent is that even though it was being used at home, the user was logging on as a client of a domain at a remote site. This prevailed for months apparently after she left their employ. I removed the machine from the domain and put it in a local workgroup. Could there be some residual trace of having been a domain client? The SP3 install had previously failed once before with same message when logged on as her local user account, even thought it was definitely in the administrator group. I thought surely the admin account itself would be able to do this, but no. Anyone got any suggestions?